Certbot is not working

Please fill out the fields below so we can help you better. Note: you must provide your domain name to get help. Domain names for issued certificates are all made public in Certificate Transparency logs (e.g. https://crt.sh/?q=example.com), so withholding your domain name here does not increase secrecy, but only makes it harder for us to provide help.

My domain is:
techchan.xyz
I ran this command:
sudo certbot --nginx

It produced this output:
Domain: techchan.xyz
Type: unauthorized
Detail: Invalid response from
http://techchan.xyz/.well-known/acme-challenge/ZO95fwL7Of5Ed6RDbin6SNTh0JSg6dQ292v-Jy5q5kY
[95.111.193.40]: “\r\n404 Not
Found\r\n\r\n

404 Not
Found

\r\n
nginx/1.17.10 (U”

To fix these errors, please make sure that your domain name was
entered correctly and the DNS A/AAAA record(s) for that domain
contain(s) the right IP address.

My web server is (include version):
nginx 1.17.10?
The operating system my web server runs on is (include version):
ubuntu 20.04 LTS
My hosting provider, if applicable, is:
upcloud
I can login to a root shell on my machine (yes or no, or I don’t know):
yes
I’m using a control panel to manage my site (no, or provide the name and version of the control panel):

The version of my client is (e.g. output of certbot --version or certbot-auto --version if you’re using Certbot): certbot 0.40.0